During the manufacture of flat panel displays, a glass substrate may be placed on a test stage for testing purposes. Typical substrate testing may include verifying the operation of thin film transistors formed on the substrate, e-beam inspection, defect detection, etc.
To accurately identify device and/or substrate locations for testing, and/or to reduce device/location search times, a position of a substrate relative to a test stage should be determined. Accordingly, improved methods and apparatus for quickly and accurately determining a position of a substrate relative to a test or other support stage would be desirable.